Most people's muscles only fire 30% of their muscle fibers, when a muscle is flexed. While apes (& other creatures), employ 100% of a muscle's fibers, when a muscle is flexed. This accounts for what is refered to as animal strength. Size of a muscle is less important, than how much of its capacity is employed. There is a fairly simple breathing/muscle flexing technique people can use, that increases the percentage of muscle fibers that fire when a muscle is flexed. Bruce Lee was aware of it, and taught it to some of his students. The result is that the person can become immensely strong, but their muscles will appear no larger than anybody else's muscles.

Training the core/stabilizer muscles is an important part of this process. You can do that with Yoga, Pilates, or Martial Arts, like Tai Chi. But there is one further step you can take, which is the real Key. This Key Principle can be applied to any physical movement form, but I will explain it here, using only the most basic form, which is Standing.

Stand in the optimally erect posture, with feet directly under the shoulders, shoulders back, & chin slightly tucked in. You should be relaxed & breathing normally. Once you have gotten into this posture & are comfortable with it, you will tense every muscle in your body at once, beginning with the transverse adominus muscle (the gut), without changing your posture the least little bit, (meaning that you will NOT raise your shoulders up, or alter the posture from simply standing at all). Then, maintaining the posture, and the tension of the muscles, you will inhale slowly & hold your breath, still without altering your posture in any way. Finally, you will relax, exhale, and remain standing in the optimal posture of standing.

This simple exercise will increase the percentage of muscle fibers that actually fire, when you flex or use your muscles. When that percentage reaches 60%, you will be effectively twice as strong, although you won't appear any different, (besides looking rather good when skyclad). Consider a 120 lbs girl, as strong as an average 240 lbs man. That can be achieved, and possibly even more...

The core/stabilizer muscles are what keep your body erect, but when they are weak or imbalanced, people develop poor posture, which limits their physical range of motion & capacity. When one core/stabilizer muscle is flexed, then all of them flex, and the easiest way to do that, is to flex the transverse adominus muscle, which is your gut muscle. Ever notice that in Martial Arts literature, they often speak of focusing in the center of gravity, the Dom Tien? This is what they are talking about.

If you use this exercise in a less than optimal posture, (like shoulders up, or back swayed to a side or something like that), you will strengthen your muscles INTO the maladapted posture. I'm sure you can see how that wouldn't work out so well. So if you have postural problems, it might be a good idea to be seeing a chiropractor, a massage therapist, AND some kind of exercise therapist, (like a Hatha Yoga, or Tai Chi instructor), before beginning to use this technique. With those three healing modalities being employed, your posture will be corrected enough to make use of this technique to its full advantage.

Using this technique with Yoga or Martial Art forms, will strengthen your body in those forms. Begin with the relaxed Standing posture. Then, tense the body & inhale, as explained above. Hold the breath while tensed in the posture, and when you exhale & relax, you move into the next posture in the series. Then you repeat this process with each form of the set. This approach will enable you to exert optimal strength in all of the motions that your body uses. It probably would be a very bad idea for someone without this training, to pick a fight with somebody who has been practicing with this technique for any amount of time... especially, if the practitioner has developed beyond 60% muscle fiber efficiency.